Process for obtaining the copper from lyes resulting from the treatment of cupriferous pyrites



Patented @ch :55, T3922 HENRI PAUL SOULIE-CUTTINEAU, 0F EARIS, FRANCE.

PROCESS FOR OBTAINING THE COPPER FROM LYES RESULTING FROMTHE TREATMENT OF CUPRIFEROUS PYRITES.

No Drawing.

To all to 710m it may concern:

Be it known that I, HENRI PAUL SoULIE- CorTINnAU, a citizen of the Republic of France, residing at 4 Rue Joullroy, Paris, Seine, France, have invented new and useful Improvements in Processes for Obtaining the Copper from Lyes Resulting from the Treatment of Cupriferous Pyrites, of which the following is a specification.

The present invention relates to improvements in processes for obtaining copper and relates more specifically to an improved process for obtaining copper from solutions resulting from the treatment of cupriit'erous pyrites.

It is an object of the invention to provided a process that will take the place of the present cementation process and that will yield an improved and purer product as compared with cement copper.

The present invention is based on the hypothesis that the production of the coppery-scale, known as cascara, should take place under conditions analogous to those which accompany the formation of native copper in nature. Now, mineralogists agree upon two points:

1. They attribute the existence of native copper to a kind of natural galvanoplastic or electrolytic action.

2. They recognize in this native copper a very clearly marked crystalline formation, octahedral crystals derived from the cubic system.

With the above two premises as a start ing point, the production of copper has been considered. as a problem analogous to crystallogeny, and the problem has been solved by the evolving of a process consisting in the following two steps:

1. The obtaining of a film of copper, however thin it may be, upon a piece of scrap iron.

2. Thickening this film in the presence of a cuprous solution in the same way as a crystal is fed in its solution.

The first step is apparently a question of galvanoplastics or electrolytic action which any one skilled in the art is able to perform, but which is carried out, according to the invention, as follows:

A wicker-work basket full of waste-iron plates or any other scrap, is suspended be- Serial No. 371,439.

neath a cock from which the liquid pours. In order that watering may take place properly, the basket is provided with a wooden lid perforated by a number of grooves in the shape of a star. Below the basket is placed a tank for collecting the solutions. The number of cocks and of baskets can be as desired. t is evident that the output of the cock and the height of fall will determine the power of the shock. l/Vith a predetermined volume of lye flowing uninterruptedly, an ascertained number of films can be prepared; with 1600 litres of lyes each having 15 grammes per litre, that is, altogether 25 lzilogrammes of copper, it has been possible with ease to start a deposit upon 1000 iron plates and cover them with a separate film for each plate, the total of such films representing 12} kilogrammes of copper. The rest of the copper contained in this solution was used for the second part of the process.

It is certain that, by continuing operations under the jet, one could obtain a larger deposit than that constituted by the deposit of a thin fihn, and then remove the film of copper from the iron, but this is quite unnecessary, as once the deposit is begun in this form, it goes on of its own accord, in accordance with the hereinafter described second part of the process.

The second step 01. the process is as follows: There is present a filni of copper which can be considered as a crystalline structure, by analogy with a crystal; this crystalline form should teed itself if the film is plunged into a cuprous solution, and experiment verifies this in all respects. It has been said above,by analogy, for the action is not identical,that a crystal is fed in the midst of its saturated solution, which is not the case here.

The copper deposits itself in the presence of the liquid which is at rest as required for crystallization, but there are phenomena of precipitation which cause the thickness of the deposit to vary from one point to another and modify the appearance and the size of the grain of the metal. For instance it a plate which is being thickened lies flat in the liquid, it will have on its lower face a film thicker than on the upper. This is due to difl'erences in the degree of concentration of the liquid and also to the mysterious and little-known action of the colloidal hydrate of iron.

In this way, deposits of copper are obtained which may be as much as 1 gramme persquare centimetre and there is no doubt that one could go further by prolonging the period of digestion.

The product obtained posseses the tenacity and malleability of the metal; it contains 98% to 99% of copper and a very low proportion, 0.35% of iron. lit-is ready for use immediately, either for melting down, for electric refining or for the manufacture of sulphate of copper. It dries in a few minutes in the open air. :All expense for fuel is avoided.

It is possible to ext act this form 100% of the copper contained in the liquors treated.

In practice, the handling rendered neces sary by the growth of the films is as simple as possible; it is sufiicient to transport the baskets mentioned to a digesting tank, where they can be left to themselves. Each basket may be provided with a label showing the date of its immersion and, from time to time, the baskets are lifted out in order to examine the state of the films. One need not hesitate to insert a knife into the film in order to ascertain its thickness, for if said thickness is not considered sufficient, the film is put back into the tank and the wound heals up, a phenomenon which presents a striking likeness with the healing up of crystals in their saturatedsolutions.

When the films are considered to be suiiiciently thick, they are readily removed by means of a flexible blade from the remaining iron. This copper is then washed, like cement copper, with a little acidulated water, allowed to dry in the open air and is then ready for use.

In the old ceinenti'tious process it is ad visable to count on a consumption of iron equal to double that of the copper obtained. ACCOICllDg to the process forming the subject of this invention, the weight of iron and copper follow the theoretical law and prac tically balance one another. The secondary reactions, which consume much iron, are avoided.

By means of the present invention, which consists in a thorough treatment of the liquids coming from the lixiviation of pyrites containing copper, one is enabled to extract from these liquids the copper in the form of a product of a value and a physical state hitherto unknown in this branch of industry without increasing the cost price, while the necessary handling operations are considerably less disagreeable and costly than the customary handling operations incident to the present processes. Furthermore, an economy is effected in fuel and iron.

It is here to be observed that by iron, as herein referred to, is understood cast iron, wrought iron, malleable cast iron,steel or any equivalent form of iron, including tinned and galvanized iron.

I claim 2- 1. A process for extracting copper from solutions resulting from the treatment of cupriferous pyrites, which consists in causing the copper to deposit electrolytically onto iron in the form of a film, and in placing the copper-coated iron in a cupriferous solution for the purpose of thickening the film of copper, said film being subsequently removed from the iron.

2. A process for extracting copper solutions used for lixiviating cupriferous pyrites, which consists in forming the copper in an initial film onto iron, such initial film being porous to ferric sulphate, and subsequently placing the iron so coated with such film in a copper solution containing ferric sulphate for the purpose of thickening the layer of copper, said layer being subsequently removed from the iron.

A process for extracting copper from solutions used for lixiviating cupriferous pyrites, consisting in causing the solution to fall upon iron and deposit copper thereon, and in placing said copper-coated iron in a cupriferous solution in order to thicken the film of copper, said film of copper being subsequently removed from the iron.

l. A process for extracting copper from solutions obtained from the treatment of cupriferous pyrites, which consists in cansing the solution containing the copper to fall upon iron whereby to deposit an initially thin crystalline film of copper thereon porous to ferric sulphate, such crystalline film having planes of cleavage between the crystals, and in subsequently placing such iron with the crystalline film thereon in a cupriferous solution containing ferric sulphate whereby the ferric sulphate may filter between the crystals and attack the iron to form a thickened. film of copper on the initial film, said thickened film being subsequently removed from the iron.

5. A process for extracting copper from solutions obtained from the treatment of cupriferous pyrites, which consists in cans ing the solution to fall upon iron for the purpose of causing copper to be electrolytically deposited thereon owing to the action of the couple iron-copper.

6. A process for extracting copper from solutions obtained from the treatment of cupriferous pyrites, which consists in causing the solution to fall upon iron for the purpose of causing copper to be electrolytically deposited thereon owing to the action of the couple iron-copper, depolarization being effected through such fall.

7. The herein described process for the recovery of copper from its solutions, which consists in suspending quantities of iron pieces beneath a falling stream of a copper solution containing ferric sulphate whereby to form a comparatively thin, initial film of crystalline character upon the iron With spaces between the crystals, such deposit being electrolytically formed owing to the action of the couple iron-copper, and subsequently placing the copper coated iron in a solution of ferric sulphate to permit the solution to filter through the spaces between the crystals and setting up further electrolytic action which feeds the crystals and thickens the film, and subsequently removing the copper from the iron.

8. The process as described of obtaining copper which consists first in forming a thin porous and non-spongy film of copper on iron and subsequently placing said iron with the copper film thereon in a solution whereby the film Will be fed and form an enlarged thick crystalline coating.

HENRI PAUL SOUl-llE-COTTINEAU. 

